IAudioDeviceManager

Interface that may be used to manage audio devices, i.e. see current active device, select another active device and get the list of available devices.

Voximplant Android SDK supports the following devices:

1. earpiece
2. speaker
3. wired headset
4. bluetooth headset

Default audio device

The earpiece is the default audio device for devices that supports telephony feature (android phones). The speaker is the default audio device for android tablets.

Before a call

In case if the audio device was not selected via IAudioDeviceManager.selectAudioDevice(AudioDevice), it will be selected according to the following priority order:

1. bluetooth (if connected)
2. wired headset (if connected)
3. earpiece (if available)
4. speaker

In case if audio device was selected via IAudioDeviceManager.selectAudioDevice(AudioDevice) and then a higher priority device is connected, the new device will be used for a call. For example, speaker was selected and then bluetooth headset is connected, in this case bluetooth device will be used for a call.

During the call

In case if new audio device (wired headset or bluetooth headset) is connected, active audio device is switched to the new connected audio device.

In case if active audio device is disconnected (wired or bluetooth headset), active audio device will be selected according to the priority order.

In case if active audio device is selected via IAudioDeviceManager.selectAudioDevice(AudioDevice), active audio device is switched to the selected device.

In case if active audio device is selected via IAudioDeviceManager.selectAudioDevice(AudioDevice) and then new audio device is connected (wired or bluetooth headset), active audio device is switched to the new audio device. If wired or bluetooth headset will be disconnected during the same call, previously selected audio device becomes active.

For example:

• wired headset is connected
• call is started -> wired headset is active device
• speaker is selected as active device -> speaker is active device
• bluetooth headset is connected -> bluetooth is active device
• bluetooth headset is disconnected -> speaker is active device

Permissions

On Android 12 or higher, the BLUETOOTH_CONNECT permission is required. The permission must be granted before the call.

Without granting this permission, Bluetooth audio devices will not be available. There is no need to request the permission on Android 11 or lower.

Connection Service

If an application uses a self-managed ConnectionService to integrate Voximplant calls with the Telecom system framework, it is important to consider that there may be the conflicts of audio routing made by the Telecom system framework and the Voximplant SDK.

This conflict may result in a wrong audio device detection (such as Bluetooth or wired headset), incorrect audio device selection and switching.

To avoid unpredictable and undesirable behavior, there are several steps to follow:

1. Check and grant the BLUETOOTH_CONNECT permission on Android 12 or higher.
2. Use IAudioDeviceManager.setTelecomConnection(Connection) API to provide a new Telecom Connection associated with a Voximplant call before the call start/answer.

Limits:

1. IAudioDeviceManager should be used only after IClient initialization via Voximplant.getClientInstance(Executor, Context, ClientConfig)
2. The plug in/out of wired headsets is monitored only if the connection to the Voximplant Cloud is active
3. Bluetooth audio devices can be monitored and used if
   • Connection to the Voximplant Cloud is active
   • BLUETOOTH_CONNECT permission is granted for an application with targetSdk 31 or higher and running on Android 12 or higher
4. It is not possible to select earpiece while a wired headset is connected